Detergent composition

Abstract

Particulate detergent compositions containing a detergent active system, sodium carbonate and a calcite seed crystal exhibit improved dispensibility from automatic washing machines when the mean particle size is at least 500 microns, such as above 700 microns and the level of particles with a size below 50 microns is less than 2% by weight of the overall composition. The Rosin-Rammler distribution n value should be at least 4 when the means particle size is 700 microns but may be as low as 2 when the mean is 1200 microns. When the sodium carbonate and calcite are in separate particles, the sizes thereof should be similar.

We claim: 
     
       1. A particulate detergent composition having improved disproved dispensibility comprising i. from 5% to 40% by weight of a detergent active system containing one or more detergent actives selected from selected from the group consisting of anionic non-soap detergent actives, nonionic detergent actives and soap;   ii. from 10% to 40% by weight of a water-soluble alkali metal carbonate selected from selected from the group consisting of sodium carbonate, potassium carbonate and mixtures thereof;   iii. from 5% to 60% by weight of a seed crystal for calcium carbonate selected from the selected from group consisting of calcite and mixtures thereof with aragonite or vaterite, the seed crystal having a surface area of at least 10 m 2  /g,   said composition being in the form of particles having a mean size of at least 500 microns, less than 2% by weight of said particles having a size of less than 50 microns, with the proviso that said particles have a Rosin-Rammler distribution n value of at least 4 if the mean particle size of the particles of the entire composition is not more than 700 microns.   
     
     
       2. A detergent composition according to claim 1, wherein the mean size of said particles is more than 700 microns. 
     
     
       3. A detergent composition according to claim 1, wherein more than 10% by weight of said particles have a particle size of more than 1700 microns. 
     
     
       4. A detergent composition according to claim 1, comprising a first group of particles containing said water-solution alkalimetal carbonate and a second group of separate different particles admixed with said particles of the first group and containing said water-insoluble carbonate material, the mean size of said first group of particles differing from the mean size of said second group of particles by not more than 500 microns.